Study on antibacterial effect of essential oils of six plant species against Pseudomonas syringae pv. syringae Van Hall 1902 and Pseudomonas fluorescens Migula 1894

This study was conducted to assess the antimicrobial activity of the essential oils of Rosmarinus officinalis, Thymus daenensis, Foeniculum vulgare, Mentha spicata, Mentha piperita and Pelargonium graveolens against Pseudomonas syringae pv. syringe (Pss). The chemical composition of essential oils of six plant species grown in Iran was analyzed by GC-MS and their inhibitory effects were studied on Pss strains IVIA 773-1 and W1 and Pseudomonas fluorescens CHA0, using the disc-diffusion method. The essential oils showed various antimicrobial activities based on the size of zone of inhibition against pathogenic and nonpathogenic bacteria on Petri plates. The minimum inhibitory concentration was evaluated by the micro broth dilution method. The results showed that all essential oils have an inhibitory effect on multiplication of the three bacterial strains tested. According to the present findings the studied essential oils have a potential to be used as antimicrobial agents.